JP2000280813A - Seated occupant detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase an accuracy for measuring a load acting on a seat. SOLUTION: This device is formed so that a sensor mounting plate on which a load sensor 62 is disposed is bridged across a seat cushion frame 18 and a seat track 27, and an occupant presence or absence identification sensor 63 is disposed on the seating part of a seat cushion 14 of a vehicle seat 10. Also, a control circuit 64 reads a value detected by the load sensor 62 as an initial value every time when the occupant presence or absence identification sensor 63 judges to be absence of an occupant, and corrects the value detected by the load sensor 62 using the initial value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seated occupant detection device, and more particularly to a seated occupant detection device applied to a seat movably disposed in the front-rear direction on the floor of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, an example of a seated occupant detection device applied to a seat movably disposed in the front-rear direction on a floor of a vehicle such as an automobile is disclosed in Japanese Patent Application Laid-Open No. 9-207638.

As shown in FIG. 7, in this seated occupant detection device, a seat mounting portion 104 for mounting a seat 100 on a floor 102 and a mounting portion 102 of the floor 102 are provided.
A is provided between the load sensors 106 and A. The number of the load sensors 106 is a minimum of two, and the positions of the load sensors 106 are the diagonal directions of the sheet mounting portions 104 normally provided at four positions. There are two places before and after. As a result, regardless of the sitting posture of the occupant, the presence or absence of the occupant can be reliably detected, and the provision of an unnecessary load sensor prevents the configuration from becoming complicated and the cost from increasing.

[0004]

However, in this seated occupant detection device, for example, the seat mounting portion 104 provided on the lower rail of the seat truck 110 and the floor 10
Since the load sensor 106 is provided at the fastening portion with
When the seat 100 is moved rearward along the seat track 110 and the seatback 100A is reclined rearward, the weight of the occupant leaning on the seatback 100A causes the front seat mounting portion 10 to move forward.
There is a case where a load acts on 4 upward. As a result, the load sensor 106 disposed on the front seat mounting portion 104
In, the load cannot be substantially measured, so that the measurement accuracy is not improved.

Further, in this seated occupant detection device, when the bolt 108 as a fastening member is tightened to increase the support rigidity of the seat 100, the initial value (initial distortion) of the load sensor 106 increases, The fluctuation value (fluctuation distortion) of the load sensor 106 caused by the load to be measured with respect to the initial value is reduced. As a result, the fluctuation value with respect to the initial value is reduced, and the measurement accuracy is not improved.

A seat occupant detection device that improves this situation is configured to determine the weight of the occupant by measuring the change in the distance between the seat cushion frame and the upper rail of the seat adjuster, that is, the distortion of the seat adjuster portion, using a sensor. Japanese Patent Application No. 11-8380 not disclosed, Japanese Patent Application No. 11-4
However, in this case, if the seat adjuster is distorted due to a change in diameter, a collision of the vehicle, or the like during assembly to the vehicle, the distortion is also measured by the sensor. However, there is a problem that the measurement accuracy of the load acting on the sheet is reduced.

The present invention has been made in view of the above circumstances, and has as its object to provide a seated occupant detection device capable of improving the measurement accuracy of a load acting on a seat.

[0008]

According to a first aspect of the present invention, there is provided a seat occupant detection device for detecting a load applied to a seat based on a distortion of a seat adjuster portion;
An occupant presence / absence determination sensor for detecting the presence / absence of an occupant seated on the seat, and each time the occupant presence / absence determination sensor determines that there is no occupant, the detection value of the load sensor is read as an initial value, and The detection value of the load sensor is corrected.

Accordingly, every time the occupant presence / absence determination sensor determines that there is no occupant, the detected value of the load sensor is read as an initial value. When distortion occurs due to a collision accident or the like, the detection value of the load sensor can be corrected based on the initial value of the load sensor changed by the distortion. As a result, the correction value is not affected by the distortion of the seat adjuster portion caused by a change in the diameter, a collision accident of the vehicle, or the like at the time of assembling to the vehicle, so that the load acting on the seat can be accurately measured. .

According to a second aspect of the present invention, there is provided a seat occupant detection device interposed between a floor and a seat cushion frame, the seat truck being capable of moving the seat cushion frame in the front-rear direction with respect to the floor. A load sensor that detects a load acting on the seat cushion frame based on a displacement of the seat cushion frame with respect to an upper rail of the seat track, and an occupant presence / absence determination sensor that detects the presence or absence of an occupant seated on a seat, Each time the occupant presence / absence determination sensor determines that there is no occupant, the detection value of the load sensor is read as an initial value, and the detection value of the load sensor is corrected by subtracting the initial value from the detection value of the load sensor. It is characterized by the following.

Therefore, every time the occupant presence / absence determination sensor determines that there is no occupant, the detected value of the load sensor is read as an initial value. If a distortion occurs due to a vehicle collision accident, the initial value of the load sensor changed by the distortion can be subtracted from the detected value of the load sensor, and the result can be used as a correction value.
As a result, the correction value is not affected by the distortion of the seat track and the seat cushion frame caused by a change in diameter, a collision accident of the vehicle, and the like at the time of assembling to the vehicle. Can measure well. Further, the load acting on the seat can be accurately measured by a simple correction of subtraction.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a seated occupant detection device according to the present invention will be described with reference to FIGS.

In the drawings, an arrow FR indicates a vehicle forward direction, an arrow UP indicates a vehicle upward direction, and an arrow IN indicates a vehicle width inside direction.

As shown in FIG. 5, a vehicle seat 10 according to the present embodiment constitutes a passenger seat of a vehicle 12, and a seat back 16 is attached to a rear portion of a seat cushion 14 so as to be rotatable in the front-rear direction. Have been.

As shown in FIG. 2, a shaft 22 is provided on the rear end portion 18A of the pair of left and right seat cushion frames 18, and the seat back pad 21, the headrest 23 and the like are provided around the shaft 22 as a center of rotation. The attached seat back frame 20 is attached so as to be rotatable in the front-rear direction. A well-known reclining mechanism (not shown) is provided at a connection portion between the seat cushion frame 18 and the seat back frame 20, and the seat back frame 20 is tilted backward with respect to the seat cushion frame 18. The angle is adjustable.

The upper and lower edges of the seat cushion frame 18 are formed with flanges 18B and 18C outwardly in the seat width direction. A pair of front and rear mounting brackets 19 are fixed to the inner surface in the seat width direction of the vertical wall portion 18D of the seat cushion frame 18, and the seat cushion pan 24 is connected to the seat cushion frame 18 via these mounting brackets 19. It is fixed to. Note that a seat cushion pad 26 is provided above the seat cushion pan 24.

As shown in FIG. 1, the seat track 27
At the front and rear ends of the lower rail 30, mounting portions 30A, 30
B are formed, and these mounting portions 30A, 30B
Are front and rear floor cross members 36, 38 disposed on the floor 34 in the vehicle width direction by bolts 32, respectively.
It is fixed to.

As shown in FIG. 4, a lower rail 30 has a lower part 28 of an upper rail 28 of the seat track 27.
A is slidably engaged in the front-rear direction of the seat, and a flange 28B is formed at the upper end of the upper rail 28 toward the outside in the seat width direction. The description and illustration of the claw and lock mechanism for fixing the position of the upper rail 28 with respect to the lower rail 30 are omitted because of their well-known structures.

As shown in FIG. 3, sensor mounting portions 40 are formed downward in the vicinity of both ends in the front-rear direction of the flange 28B of the upper rail 28, and the sensor mounting portions 40 have a side view shape. And an inverted trapezoidal shape. On the other hand, sensor mounting portions 42 are formed upward in the vicinity of both ends in the front-rear direction of the lower flange 18C of the seat cushion frame 18, and the shape of the sensor mounting portions 42 in a side view is trapezoidal. ing. A sensor mounting plate 44 is provided between the sensor mounting portion 40 of the upper rail 28 and the sensor mounting portion 42 of the seat cushion frame 18, and the upper rail 28 and the seat cushion frame 18 are located at a position facing the sensor mounting plate 44. They are connected by a bracket 46.
Each of the sensor mounting plate 44 and the bracket 46 has a rectangular shape whose longitudinal direction is the vertical direction when viewed from the side.

As shown in FIG. 4, the bracket 46
Due to the vertical load acting between the upper rail 28 and the seat cushion frame 18, the upper rail 28 is compressed and deformed in the vertical direction as shown by a two-dot chain line in FIG.
Although the distance between the seat cushion frame 18 and the seat cushion frame 18 is changed, the seat cushion frame 18 has sufficient rigidity to prevent breakage. When the load is removed, the bracket 46 needs to return to the original shape shown by the solid line in FIG. 4, so it is necessary to use spring steel or to increase the angle θ of the bent portion. It is. In particular, if there is no restriction on the relationship with surrounding parts, FIG.
As shown in FIG.

Near the upper and lower ends of the sensor mounting plate 44,
Attachment holes 48 are respectively formed, and these attachment holes 48 are elongated holes whose longitudinal direction is the vertical direction. Also, the sensor mounting portion 42 of the seat cushion frame 18
The upper rail 28 has a mounting hole 50 formed therein.
A mounting hole 52 is formed in the sensor mounting portion 40. Mounting hole 48 and mounting hole 50 and mounting hole 48 and mounting hole 5
2, bolts 54 are inserted from the outside in the sheet width direction, and screw portions 54 </ b> A of these bolts 54 are inserted.
Are screwed into weld nuts 56 disposed on the inner side in the sheet width direction of the sensor mounting portions 42 and 40, respectively.
The bracket 46 has an upper end 46A welded to a vertical wall 18D of the seat cushion frame 18, and a lower end 46B welded to a vertical wall 28C of the upper rail 28. The bent portion 46C formed in the middle portion of the bracket 46 in the up-down direction has a V-shape when viewed from the front-rear direction of the seat, and when the occupant 60 is seated on the seat 10, the load is reduced by the load. As shown by the two-dot chain line in FIG. 4, the bent portion 46C of the bracket 46 is compressed and deformed in the vertical direction, and the seat cushion frame 18 is lowered (see FIG. 4).
(In the direction of arrow A). Further, the sensor mounting plate 44 is formed of a thin plate, and a load sensor 62 formed of a sheet-shaped strain measuring sensor is disposed on the outer surface 44B in the sheet width direction of the central portion 44A in the vertical direction. Therefore, when the seat cushion frame 18 moves downward (in the direction of arrow A in FIG. 4), the vertical intermediate portion 44A of the sensor mounting plate 44 curves outward in the seat width direction, and the distortion at this time is reduced by the load sensor 62. Can be detected by

As shown in FIG. 5, an occupant presence / absence discriminating sensor 63 is provided at a seating portion of the seat cushion 14 of the vehicle seat 10. This occupant presence / absence determination sensor 63
Is disposed between the pad of the seat cushion 14 and the skin, and includes a well-known pressure-sensitive film sensor, a capacitance sensor, and the like.

As shown in FIG. 1, the load sensor 62 and the occupant presence / absence discriminating sensor 63 are connected to a control unit 64. The control unit 64 includes an impact sensor 66 and an assistant disposed in an instrument panel 68. It is connected to the seat airbag device 70. In addition, the control unit 64 includes collision detection input data from the impact sensor 66, occupant presence / absence data from the occupant presence / absence determination sensor 63, and input data from the load sensor 62 used to determine the occupant's physique, etc. The control of the inflator and the output control of the airbag device 70 for the passenger seat are performed based on the occupant presence sensor 63 each time the occupant presence / absence determination sensor 63 determines that there is no occupant.
2 is read as an initial value, and the detected value of the load sensor 62 is corrected based on the initial value.

Next, the operation of this embodiment will be described in detail with reference to the flowchart shown in FIG.

In this embodiment, when the control unit 64 and the like are energized by the operation of the ignition key by the occupant, as shown in FIG.
In step 4, the steps in the flowchart (hereinafter referred to as S)
At 100, the output signal of the occupant presence / absence determination sensor 63 is read.

Next, in S102, it is determined whether or not the occupant is seated on the seat 10 based on the output signal of the occupant presence / absence determination sensor 63. In S102,
If it is determined that the occupant is not sitting on the seat 10 (no occupant), the process proceeds to S104 and the timer T is started. Next, in step S106, a timer T is set to prevent chattering of the occupant presence / absence determination sensor 63 and erroneous detection due to electric noise when the vehicle is traveling on a rough road.
Returns to S100 until the time becomes equal to or longer than the predetermined time T1, and moves to S108 when the timer T becomes equal to or longer than the predetermined time T1.
In S108, the detection value of the load sensor 62 is read as the initial value So, and the process returns to S100.

On the other hand, if it is determined in S102 that the occupant is seated on the seat 10 (occupant is present), the process proceeds to S102.
The process moves to 110 and the timer T is started. Next, S112
In order to prevent chattering of the occupant presence / absence determination sensor 63 due to slight movement of the occupant when the vehicle is traveling on a bad road, and to prevent erroneous detection due to electric noise,
The process returns to S100 until the timer T becomes equal to or longer than the predetermined time T2.
Move to 4. In S114, the detection value Sd of the load sensor 62
Is read, and in S116, the detected value Sd
Then, a correction value (Sd-So) is calculated by subtracting the initial value So from the above, and it is determined whether or not the correction value (Sd-So) is larger than the threshold value S.

In S116, the correction value (Sd-So)
Is larger than the threshold value S, the process proceeds to S118 and the timer T is started. Next, in step S120, a timer T is used to prevent chattering of the occupant presence / absence determination sensor 63 due to slight body movement of the occupant when the vehicle is traveling on a bad road, and erroneous detection due to electric noise.
Only when the predetermined time is equal to or longer than the predetermined time T2, the process proceeds to S122, and the passenger airbag device 70 is set in an operable state.

On the other hand, at S116, the correction value (Sd-
So) is not determined to be greater than the threshold value S, or
If the timer T does not reach the predetermined time T2 or more in S120, the process proceeds to S124, and the operation of the airbag device 70 for the passenger seat is prohibited.

As described above, in the present embodiment, the detection value of the load sensor 62 is read as the initial value each time the occupant presence / absence determination sensor 63 determines that there is no occupant. ,
When distortion occurs due to a change in diameter, a collision accident of the vehicle, or the like at the time of assembling to a vehicle, the initial value So of the load sensor 63 changed by the distortion is determined by the detection value Sd of the load sensor 63.
Can be subtracted from the correction value (Sd-So) of the load sensor. As a result, the correction value is not affected by the distortion of the seat cushion frame 18 and the seat track 27 caused by a change in diameter, a collision accident of the vehicle, and the like at the time of assembling to the vehicle. Load can be measured accurately. Further, the load acting on the seat 10 can be accurately measured by a simple correction of subtraction.

In this embodiment, the weight of the occupant 60 mainly acts on the rear portion 14A of the seat cushion 14 and the seat back 16, as shown by arrows F1 and F2 in FIG. As a result, since the upper rail 28 is pressed downward, as shown by the two-dot chain line in FIG. 4, the bent portion 46C of the bracket 46 is compressed and deformed in the vertical direction, and the seat cushion frame 18 is lowered (arrow A in FIG. 4). Direction)
The distance between the seat cushion frame 18 and the upper rail 28 is reduced. At this time, as shown by a two-dot chain line in FIG. 4, the middle part 44A in the vertical direction of the sensor mounting plate 44 is bent outward in the sheet width direction.
Can be detected.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included in the scope of the present invention. It is clear to a person skilled in the art that is possible. For example, in the present embodiment, the occupant presence / absence determination sensor 6 is mounted on the seat portion of the seat cushion 14 of the vehicle seat 10.
The occupant presence / absence determination sensor 63 is constituted by a known pressure-sensitive film sensor, a capacitance sensor, or the like. However, the occupant presence / absence determination sensor 63 is not limited to this, and is indicated by a two-dot chain line in FIG. As described above, a non-contact sensor 71 such as an infrared sensor or an ultrasonic sensor may be provided on the instrument panel 68. Further, the non-contact type sensor 71 may be provided on a roof or the like other than on the instrument panel 68. Further, in the present embodiment, the configuration is such that the passenger airbag device 70 is operated, but other airbag devices such as a side airbag device may be operated in addition to the passenger airbag device 70. . Further, the mounting position and the mounting method of the load sensor 62 are not limited to the present embodiment.

[0033]

According to the first aspect of the present invention, there is provided a seat occupant detection apparatus for detecting a load acting on a seat based on distortion of a seat adjuster portion, and an occupant detecting presence or absence of an occupant seated on the seat. Each time the occupant presence / absence determination sensor determines that there is no occupant, reads the detection value of the load sensor as an initial value and acts on the seat to correct the detection value of the load sensor based on the initial value. It has an excellent effect that the measurement accuracy of the load can be improved.

According to a second aspect of the present invention, there is provided a seat occupant detection device interposed between a floor and a seat cushion frame, the seat truck being capable of moving the seat cushion frame in the front-rear direction with respect to the floor. A load sensor that detects a load acting on the seat cushion frame based on the displacement of the seat cushion frame with respect to the upper rail, and an occupant presence / absence determination sensor that detects the presence or absence of an occupant seated on the seat. Each time it is determined that there is no occupant, the load sensor reading value is read as the initial value, and the load sensor is corrected by subtracting the initial value from the load sensor detection value to correct the load sensor detection value. Has an excellent effect that can be improved. Further, there is an excellent effect that the load acting on the seat can be measured with high accuracy by a simple correction of subtraction.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a part of a vehicle to which a seated occupant detection device according to one embodiment of the present invention is applied.

FIG. 2 is an exploded perspective view showing a seat to which the seated occupant detection device according to the embodiment of the present invention is applied, as viewed obliquely from the front outside of the vehicle.

FIG. 3 is an exploded perspective view showing a part of a seat of the seated occupant detection device according to the embodiment of the present invention, as viewed obliquely from the front outer side of the vehicle.

FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a schematic perspective view showing a front part of a vehicle compartment to which a seated occupant detection device according to one embodiment of the present invention is applied.

FIG. 6 is a flowchart showing control in a seated occupant detection device according to one embodiment of the present invention.

FIG. 7 is a schematic side view showing a part of a vehicle to which a seated occupant detection device according to a conventional embodiment is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Seat 14 Seat cushion 16 Seat back 18 Seat cushion frame 20 Seat back frame 28 Upper rail of seat truck 30 Lower rail of seat truck 62 Load sensor 63 Occupant presence / absence sensor 64 Control unit

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Claims (2)

[Claims] An occupant presence / absence determination sensor comprising: a load sensor for detecting a load acting on a seat based on a distortion of a seat adjuster portion; and an occupant presence / absence determination sensor for detecting the presence / absence of an occupant seated on the seat. A seated occupant detection device, wherein each time it is determined that there is no occupant, the detection value of the load sensor is read as an initial value, and the detection value of the load sensor is corrected based on the initial value. 2. A seat track interposed between a floor and a seat cushion frame for enabling the seat cushion frame to move in the front-rear direction with respect to the floor, and displacement of the seat cushion frame with respect to an upper rail of the seat track. A load sensor that detects a load acting on the seat cushion frame based on the above, and an occupant presence / absence determination sensor that detects the presence / absence of an occupant seated on the seat, and wherein the occupant presence / absence determination sensor determines that there is no occupant. A detection value of the load sensor is read as an initial value, and the detection value of the load sensor is corrected by subtracting the initial value from the detection value of the load sensor.